The ALADIN code is following the ARPEGE one in its permanent evolution (see history of ALADIN cycles). This is due mainly to the technical evolution of calculating machines (CDC, CRAY 2, CRAY C90, FUJITSU, NEC...) which imposes a new adaptation of the code to the new machine properties.
The evolution of the number of observations over the world dictates also a code development if one wants to take new observations into account.
In addition to these two external constraints, code must contain the newest coding rules if one wants to have a permanent portable one, ...
Code optimization, as bugs correction, compas bugs correction, computation time and memory winning, ... is also another constraint.
And of course, the evolution of the code is also imposed by the new developments (a development usually involves another one !).
Phasing is centralized in Toulouse since a very close co-operation between ALADIN and ARPEGE scientists is required for this crucial exercise. The stays are usually 6 weeks long, costs may be supported by Météo-France. Deported validation of cycles are accepted as contributions to phasing exercises exceptionally, for technical options that cannot be validated in Toulouse.
A Phasers’ guide defines the rules of these phasings :
A Phasing roadmap summarizes the phasing general rules on source code and draws phasing roadmap of actions.
Newsletter 8, published on January 31st, 2017